Instructional Text on the UI
Embedded assistance makes us reevaluate some tried and true principles of information design because our instructions occur within an action-packed medium--an application's user interface. If you think you have trouble holding a student's attention in the classroom, try teaching in a video-arcade. In many ways, embedded assistance has the same challenge.
Having said that, I'm going to shoot you over to a column I wrote a year ago for UXmatters called Instructional Text in the User Interface: Some Counterintuitive Implications of User Behaviors .